This application is based upon and claims the benefit of priority of Japanese Patent Application No. 2000-114975 filed on Apr. 17, 2000, the content of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a compressor having an oil separator in which, after refrigerant including lubrication oil is sucked and compressed for lubricating compressor mechanisms, lubrication oil is separated from refrigerant before refrigerant is discharged to outside of the compressor, preferably, applicable to a scroll type compressor for vehicle refrigeration cycle.
2. Description of Related Art
As disclosed in JP-A-7-151083, a conventional compressor for refrigeration cycle has an oil separation chamber constituting a part of an oil separator for separating oil from refrigerant since, if refrigerant including lubricant oil is discharged to an outside of the compressor, refrigeration cycle efficiency decreases.
Further, Jp-A-11-82352 discloses a compact oil separator in which lubrication oil is separated from refrigerant without enlarging an entire body of the compressor.
As shown in FIG. 9 illustrating cross sectional views of the conventional oil separator and an outside discharge pipe 20 connected to the oil separator, the conventional oil separator is composed of an oil separation chamber 11 having introduction and ejection holes 13 and 14, which is formed in a rear housing 4 of the compressor, and a composite joint-separator pipe 12 having a separator pipe 12a and a joint 12b that are integrated into one body, which are fastened and fixed via an O ring 16 for seal to the rear housing 4 by bolts 17.
While the outside discharge pipe 20 is inserted and fitted via another O ring 21 for seal to an inner bore of the composite joint-separator pipe 12, the outside discharge pipe 20 is fastened and fixed via the joint 12 to the rear housing 4 by bolts 22. The composite joint-separator pipe 12 is formed by machining so that manufacturing cost thereof is expensive.
An object of the invention is to provide a compressor having an oil separator whose construction is simple and manufactured at less cost.
To achieve the above object, in a compressor connected to a discharge pipe for transferring discharged refrigerant to outside, an oil separator is composed of a separation chamber which is formed in a housing and whose one end is opened to a surface of the housing, introduction and ejection bores provided on a wall of the separation chamber and a separator pipe having a large diameter portion and a small diameter portion both of which are inserted into the separation chamber.
With the oil separator mentioned above, the large diameter portion is fixed to an inner wall of the separation chamber in a vicinity of the opening end thereof so that circumferential space between the small diameter portion and the inner wall of the separation chamber is formed so as to communicate the introduction bore with the ejection bore. Further, the discharged pipe is fluid-tightly connected and fixed to the housing at the opening end of the separation chamber.
The separator pipe of the oil separator mentioned above, which may be formed just by pressing a pipe member, is manufactured at lower cost due to better productivity and less material, compared with the conventional composite joint-separator pipe formed by machining. Further, it is not necessary to have the O ring for sealing and the bolts by which the joint is fixed to the housing and to provide screw holes into which the bolts are fastened.
Furthermore, the discharge pipe can be connected directly, not through the joint, to the housing, which is compact and simple in its construction. Moreover, since it is not necessary to fix fluid-tightly the separator pipe to the inner wall of the housing and only the discharge pipe is fluid-tightly connected to the housing, a less number of sealing members such as the O ring is required so that reliability of the oil separator is improved.
It is preferable that the large diameter portion of the separator pipe is press fitted to the inner wall of the separation chamber. The press fitting for fixing is easier than the other fixing processes such as bolt fastening and welding.
Further, preferably, the separation chamber is provided on the inner wall thereof with a step portion which can retain the separator pipe so that the separator pipe is restricted from moving in an opposite direction to the opening end in the separation chamber. It is preferable that the step portion retains an end of the large diameter portion on a side of the small diameter portion or a flange provided on the large diameter portion.
Furthermore, it is preferable that an end of the large diameter portion on a side of the opening end is positioned to face an end of the discharge pipe. With this construction, the separator pipe is restricted by the end of the discharge pipe from coming out the separation chamber toward outside.
Preferably, a slight gap is formed between the end of the large diameter portion on a side of the opening end and the end of the discharge pipe. The slight gap serves to prevent the end of the discharge pipe from hitting against the end of the separator pipe so that fitting seat surface of the discharge pipe comes in close contact with fitting seat surface of the housing to secure the fluid-tightness when the discharge pipe is fixed to the housing.